This is a proposal for NICHD R24 infrastructure support for the 40 research associates at the Office of Population Research (OPR) at Princeton University. OPR has fostered research and training in population since it was founded in 1936; it has received infrastructure support from NICHD since 1979. Research at OPR is now characterized by five signature themes: (1) health and well-being, (2) migration and development, (3) children and families, (4) social inequality, and (5) data/methods. We seek support for five infrastructure cores. The Administrative Core will support intellectual interaction through the Notestein Seminar Series and will support individual research associates primarily by helping with grant preparation and management. The Computing and Statistics Core will support individual research associates by keeping the computing infrastructure state-of-the-art and by providing statistical and econometric consulting. The Information Retrieval Core will support individual research associates by helping them identify and retrieve scholarly publications and data and will support the entire population community by continuing to build and maintain the Ansley J. Coale Population Research Collection. The Developmental Infrastructure Core has two components. Pilot grants for junior faculty and junior research staff will provide salary or other research support in developing a project to the state at which a research proposal can be submitted to an external funding agency; these will be awarded on a competitive basis. Professional development workshops will allow all OPR research associates to develop and strengthen research skills. The Public Infrastructure Core has six components. The Data Archive will make demographic data available to the worldwide community of scholars. The Population Annual Meeting Program Application will be used by the PAA and IUSSP to manage their professional meetings. The Working Paper Series will allow prepublication access to research findings via the Web. The Research Brief Series will translate research findings in language understood by policymakers. The Emergency Contraception Website will provide accurate information about emergency contraception derived from the medical literature and a directory of providers of emergency contraceptives. The journal Future of Children will promote effective policies and programs for children by providing policymakers, service providers, and the media with information based on the best available research.